This invention relates to novel high purity glycoproteins having activity as trypsin inhibitors and inhibitors of endothelial cell growth.
It is known that proteinase inhibitors are widely distributed in animal tissues and body fluids. Some of these inhibitors have been suggested as important mediators of proliferative and invasive processes which affect developing or diseased tissues.
In particular, various cartilaginous and other such connective tissues have been described heretofore as sources of proteinase inhibitors. Kuettner et al, Experientia 30, 595-7 (1974). Subsequently, Kuettner et al, Biochem. Biophys. Res. Comm. 72 (1), 40-6 (1976), disclosed the isolation of a specific cationic trypsin inhibitor having a molecular weight of about 11,000. The material was derived from bovine cartilage by guanidinium hydrochloride extraction, ultrafiltration and Sephadex.RTM. G-75 chromatography.
In another report from the foregoing investigators, trypsin inhibitors having molecular weights of 12,300 and 11,500 were reported to be isolated from bovine cartilage and aorta, respectively. Sorgente et al, Protides of Biol. Fluids, Proc. Colloq. 23, 227-30 (1976). The latter two inhibitors were obtained by extraction with guanidinium chloride and 2-(N-morpholino)-ethanesulfonic acid followed by dialysis, Sephadex CM-50 cation exchange, gel exclusion and affinity chromatography on insolubilized trypsin.
In U.S. Pat. No. 4,042,457, Kuettner et al, disclose the preparation of inhibitor substances from cartilage and other connective tissues having molecular weights below about 50,000. The materials are said to be effective for inhibiting cell proliferation and tissue invasion. In still another paper by these investigators, Eisenstein et al, Amer. J. Path. 81, 337-48 (1975), it is stated that the cartilage material having a molecular weight of 50,000 or above had no inhibitory effect on growth of endothelial cells in doses as high as 500 .mu.g/ml.
Another group of investigators, Langer et al., Science 193, 80-2 (1976), disclosed the preparation of a cartilage factor having a molecular weight between about 14,400 and 17,800 which was shown to have trypsin inhibitory activity and activity that inhibits tumor neovascularization.